- djm@cvs.openbsd.org 2011/05/04 21:15:29

     [authfile.c authfile.h ssh-add.c]
     allow "ssh-add - < key"; feedback and ok markus@

1 files changed, 64 insertions, 36 deletions

diff --git a/authfile.c b/authfile.c
index a49850c89..608d1d06f 100644
--- a/authfile.c
+++ b/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.87 2010/11/29 18:57:04 markus Exp $ */
+/* $OpenBSD: authfile.c,v 1.88 2011/05/04 21:15:29 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -69,6 +69,8 @@
 #include "misc.h"
 #include "atomicio.h"
 
+#define MAX_KEY_FILE_SIZE       (1024 * 1024)
+
 /* Version identification string for SSH v1 identity files. */
 static const char authfile_id_string[] =
     "SSH PRIVATE KEY FILE FORMAT 1.1\n";
@@ -312,12 +314,12 @@ key_parse_public_rsa1(Buffer *blob, char **commentp)
         return pub;
 }
 
-/* Load the contents of a key file into a buffer */
-static int
+/* Load a key from a fd into a buffer */
+int
 key_load_file(int fd, const char *filename, Buffer *blob)
 {
+        u_char buf[1024];
         size_t len;
-        u_char *cp;
         struct stat st;
 
         if (fstat(fd, &st) < 0) {
@@ -325,30 +327,45 @@ key_load_file(int fd, const char *filename, Buffer *blob)
                     filename == NULL ? "" : filename,
                     filename == NULL ? "" : " ",
                     strerror(errno));
-                close(fd);
                 return 0;
         }
-        if (st.st_size > 1*1024*1024) {
+        if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+            st.st_size > MAX_KEY_FILE_SIZE) {
+ toobig:
                 error("%s: key file %.200s%stoo large", __func__,
                     filename == NULL ? "" : filename,
                     filename == NULL ? "" : " ");
-                close(fd);
                 return 0;
         }
-        len = (size_t)st.st_size;               /* truncated */
-
         buffer_init(blob);
-        cp = buffer_append_space(blob, len);
-
-        if (atomicio(read, fd, cp, len) != len) {
-                debug("%s: read from key file %.200s%sfailed: %.100s", __func__,
-                    filename == NULL ? "" : filename,
-                    filename == NULL ? "" : " ",
-                    strerror(errno));
+        for (;;) {
+                if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
+                        if (errno == EPIPE)
+                                break;
+                        debug("%s: read from key file %.200s%sfailed: %.100s",
+                            __func__, filename == NULL ? "" : filename,
+                            filename == NULL ? "" : " ", strerror(errno));
+                        buffer_clear(blob);
+                        bzero(buf, sizeof(buf));
+                        return 0;
+                }
+                buffer_append(blob, buf, len);
+                if (buffer_len(blob) > MAX_KEY_FILE_SIZE) {
+                        buffer_clear(blob);
+                        bzero(buf, sizeof(buf));
+                        goto toobig;
+                }
+        }
+        bzero(buf, sizeof(buf));
+        if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+            st.st_size != buffer_len(blob)) {
+                debug("%s: key file %.200s%schanged size while reading",
+                    __func__, filename == NULL ? "" : filename,
+                    filename == NULL ? "" : " ");
                 buffer_clear(blob);
-                close(fd);
                 return 0;
         }
+
         return 1;
 }
 
@@ -670,11 +687,38 @@ key_load_private_type(int type, const char *filename, const char *passphrase,
 }
 
 Key *
+key_parse_private(Buffer *buffer, const char *filename,
+    const char *passphrase, char **commentp)
+{
+        Key *pub, *prv;
+        Buffer pubcopy;
+
+        buffer_init(&pubcopy);
+        buffer_append(&pubcopy, buffer_ptr(buffer), buffer_len(buffer));
+        /* it's a SSH v1 key if the public key part is readable */
+        pub = key_parse_public_rsa1(&pubcopy, commentp);
+        buffer_free(&pubcopy);
+        if (pub == NULL) {
+                prv = key_parse_private_type(buffer, KEY_UNSPEC,
+                    passphrase, NULL);
+                /* use the filename as a comment for PEM */
+                if (commentp && prv)
+                        *commentp = xstrdup(filename);
+        } else {
+                key_free(pub);
+                /* key_parse_public_rsa1() has already loaded the comment */
+                prv = key_parse_private_type(buffer, KEY_RSA1, passphrase,
+                    NULL);
+        }
+        return prv;
+}
+
+Key *
 key_load_private(const char *filename, const char *passphrase,
     char **commentp)
 {
-        Key *pub, *prv;
-        Buffer buffer, pubcopy;
+        Key *prv;
+        Buffer buffer;
         int fd;
 
         fd = open(filename, O_RDONLY);
@@ -697,23 +741,7 @@ key_load_private(const char *filename, const char *passphrase,
         }
         close(fd);
 
-        buffer_init(&pubcopy);
-        buffer_append(&pubcopy, buffer_ptr(&buffer), buffer_len(&buffer));
-        /* it's a SSH v1 key if the public key part is readable */
-        pub = key_parse_public_rsa1(&pubcopy, commentp);
-        buffer_free(&pubcopy);
-        if (pub == NULL) {
-                prv = key_parse_private_type(&buffer, KEY_UNSPEC,
-                    passphrase, NULL);
-                /* use the filename as a comment for PEM */
-                if (commentp && prv)
-                        *commentp = xstrdup(filename);
-        } else {
-                key_free(pub);
-                /* key_parse_public_rsa1() has already loaded the comment */
-                prv = key_parse_private_type(&buffer, KEY_RSA1, passphrase,
-                    NULL);
-        }
+        prv = key_parse_private(&buffer, filename, passphrase, commentp);
         buffer_free(&buffer);
         return prv;
 }